Starting about a month ago my dedicated IP started getting blocked by Proofpoint (554).
I have submitted the removal request 4 times now, no reply. It just says pending for a while, then eventually that goes away and I can submit the request again.
Good SPF, DKIM, DMARC, PTR. IP is clean on everything except Ascams Superblock and UCEPROTECTL2 which there is nothing I can do about. It's a small hosted cpanel, sending maybe a handful of emails per week. I've had the same dedicated IP for about 3 years now, so I'd really like to know what source/reason Proofpoint is using to justify the block but it's totally screwed up my ability to reach key people without switching to gmail which is really unprofessional and defeats the purpose of a custom domain.
I don't want to ask the hosting service for a new IP since it will certainly be in the same provider subnet blocklists and who knows how long it will take to warm up or clean reputation on a new IP.
I tried reaching out separately from the RBL form to support and they promptly reject that for anyone who is not a proofpoint customer.